﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace DaoHam
{
    public abstract class BieuThuc
    {
        virtual public BieuThuc TinhDaoHam()
        {
            return null;
        }
        virtual public float TinhBieuThuc(float x)
        {
            return 0;
        }

        virtual public string XuatBieuThuc()
        {
            return "";
        }

        virtual public string ToString(Convert cv)
        {
            return "";
        }
    }
}
